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Providing evidence to improve practice

Individual study: Management of semi-natural blanket bog in the northern Pennines

Published source details

Rawes M. & Hobbs R. (1979) Management of semi-natural blanket bog in the northern Pennines. Journal of Ecology, 67, 789-807


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Exclude or remove livestock from degraded peatlands Peatland Conservation

A replicated, paired, controlled, before-and-after study in 1953–1975 in a grazed blanket bog in England, UK (Rawes & Hobbs 1979) found that excluding sheep typically had no effect on heather Calluna vulgaris or cottongrass Eriophorum spp. cover, but had mixed effects on moss cover. In two of three sites, plots from which sheep had been excluded had similar cover to grazed plots of heather (exclusion: 60–70%; grazed: 50–60%) and cottongrasses (exclusion: 7%; grazed: 7%). Meanwhile in a third site, around a bog pool, cover increased over 21 years of sheep exclusion for both heather (from 40 to 54%) and cottongrasses (from 0 to 2%). Moss cover showed mixed responses to sheep exclusion: both Sphagnum and other moss cover were lower in exclusion plots than grazed plots in one site (exclusion: 3%; grazed: 4–5%), similar in exclusion and grazed plots in one site (exclusion: 1%; grazed: 1%), but showed mixed responses by species around the bog pool. In 1953 or 1968, sheep were excluded from part of each site with 20 cm mesh fencing. The rest of each site remained grazed (<0.3 sheep/ha). Vegetation cover was recorded after 7, 18 or 12 years of exclosure (and immediately before exclosure in the bog pool site).

(Summarised by Nigel Taylor)

Use prescribed fire to control problematic plants Peatland Conservation

A replicated, randomized, paired, controlled study in 1954–1973 in a blanket bog in England, UK (Rawes & Hobbs 1979) found that repeatedly burned plots developed less heather Calluna vulgaris cover and greater cover of some mosses than once-burned plots, but that cover of cottongrasses Eriophorum spp. was similar under both treatments. After 18 years, twice-burned plots consistently had less heather cover (19–30%) than once-burned plots (67–82%). Twice-burned plots also had greater cover of rusty swan-neck moss Campylopus flexuosus in 3 of 4 comparisons (for which twice-burned: 38–46%; once-burned: 11–22%) and Sphagnum mosses in 2 of 4 comparisons (when sheep were excluded; twice-burned: 19%; once-burned: 5%). All plots had similar cover of six other moss species (see original paper) and cottongrasses (twice-burned: 8–67%; once-burned: 6–62%). Mixed responses to burning were reported for 26 other plant groups. In 1954, four areas (each containing six 1,000 m2 plots) in a historically grazed bog were burned. Within each area, two random plots were burned again in 1965 whilst four plots were not burned again. Half of the plots were also fenced to exclude sheep. In 1972, vegetation cover was estimated by recording, in each plot, plants touching 250 randomly placed pins.

(Summarised by Nigel Taylor)

Exclude or remove livestock from degraded peatlands Peatland Conservation

A replicated, randomized, paired, controlled study in 1954–1973 in a grazed and recently burned blanket bog in England, UK (Rawes & Hobbs 1979) found that excluding sheep typically had no effect on vegetation cover, but did increase the number of heather Calluna vulgaris shoots and stems. For 32 of 37 plant groups, cover never significantly differed between plots from which sheep had been excluded and plots that remained grazed. These included Sphagnum mosses (exclusion: 5–19%; grazed: 2–8%), six of seven other moss species (exclusion: 1–38%; grazed: 1–46%), cottongrasses Eriophorum spp. (exclusion: 6–62%; grazed: 9–67%) and live heather (exclusion: 30–82%; grazed: 19–70%). However, exclusion plots did contain a greater density of heather shoots and stems than grazed plots. In 1954, four areas of a grazed bog (<0.3 sheep/ha) were burned once. Within each area, a random three of six 1,000 m2 plots were fenced to exclude sheep. In each area, one fenced and one unfenced plot were burned again in 1965. In 1972, vegetation cover was estimated by recording, in each plot, plants touching 250 randomly placed pins. This study was based on the same experimental set-up as (7) and (8).

(Summarised by Nigel Taylor)